The present invention relates generally to fluid-handling systems, and more particularly to devices or systems that are capable of formulating, storing, dispensing, or regulating the flow of fluids.
The development, production and sales of countless industrial and consumer products involve fluid-handling operations (e.g., flow regulation, dispensing fluids, storing fluids, mixing fluids, etc.). Fluid-handling systems are used to perform these operations.
One application for fluid-handling systems is in the production of xe2x80x9cformulations.xe2x80x9d Formulations are produced by the physical combination of two or more fluids or fluidized ingredients. Formulation ingredients are often liquid, or otherwise liquefied, so that they flow under appropriate conditions.
To create a formulation, the ingredients are usually transported (e.g., pumped, etc.) to a receiver, where they are physically (and sometimes chemically) combined, typically in precise amounts. For some formulations, this xe2x80x9ccombiningxe2x80x9d operation occurs in a production facility; for others, it occurs at the point of sale by a retailer, etc. Once a formulation is produced, it is typically packaged and then, at an appropriate time, dispensed for use. For some applications, an ability to dispense a precise amount of the formulation is required; for some others, it""s not.
Many different products are properly characterized as xe2x80x9cformulationsxe2x80x9d under the definition provided above. Examples include personal-care products (e.g., shampoo, perfume, etc.), household cleaning products ((e.g., liquid dishwashing detergents and clothes-cleaning detergents, etc.), foods (e.g., cream cheese, ice cream, margarine, etc.), industrial products (e.g., engine oil, lubricants, industrial cleaners, etc.), adhesives (e.g. glues, resins, etc.), paints and coatings, pharmaceutical products, and electronics xe2x80x9cchemicalsxe2x80x9d (e.g., solder masks, etch resist masks, etc.), to name but a few.
The products listed above, which are but a small subset of the universe of formulated products, vary widely as to their rheological properties. Furthermore, formulation applications present substantial application-to-application differences in the relative amounts of ingredients and in the amount of product being formulated. Compare, for example, commercial-scale production of a food (e.g., mayonnaise, etc.) versus a point-of-sale apparatus for formulating paints in one-quart to five-gallon batches (e.g., for home-owners, etc.). Additionally, the specific fluid-handling operations being performed will vary (e.g., transporting vs. mixing vs. dispensing, etc.). Consequently, fluid-handling systems and components that are used for the production of formulations are implemented in a wide variety of application-specific designs and configurations.
By way of example, for some formulation applications, fluid-handling systems include special pumps that are used to pressurize liquid for transport or dispensing. In some other applications, syringes are used to deliver product. In yet further applications, pipettes are coupled to systems capable of pressurizing fluids for dispensing. Often, fluid-handling requires emulsification or mixing of ingredients. Some fluid-handling systems are available as xe2x80x9cbottle-topxe2x80x9d dispensers that directly couple to a bottle of liquid to dispense the liquid contained therein. But some other systems are quite complicated and include their own fluid reservoirs, control systems, etc.
Some formulation ingredients and formulated products present special difficulties for fluid-handling systems. For example, formulation ingredients (or formulated products) that are high-viscosity liquids, high-solids-concentration liquid suspensions, non-Newtonian fluids, and the like cause problems for rotating equipment, such as pumps. Among other problems, it is difficult to control the flow rate of such materials. Consequently, special pumps are required.
Furthermore, as implied above, some prior-art fluid-handling systems are equipment-intensive. In particular, these systems typically include one fully-controllable pump for each ingredient in the formulation. Such systems are often relatively expensive. And prior-art fluid-handling systems often require substantial maintenance. This maintenance includes servicing the rotating equipment (e.g. pumps, etc.) to keep it operational and cleaning the system regularly to prevent clogging. Clogging is particularly likely when the formulation ingredients are high-viscosity liquids, polymerizable materials, and high-solids-concentration suspensions. Additionally, to avoid contamination, these systems must be cleaned whenever the formulation is changed.
The art would therefore benefit from a fluid-handling system that, among another attributes, has a configuration or structure that is less application-sensitive than prior-art systems. In particular, the fluid-handling system should possess at least some of the following attributes:
Suitable for use with products over a wide range of rheological properties (e.g., low viscosity to high viscosity, etc).
Suitable for use over a wide range of capacity (e.g., flow rate, amount of ingredients, etc).
Not as maintenance-intensive as prior-art fluid-handling systems.
Suitable for use in a variety of applications (e.g., storage, mixing, dispensing, etc.).
A fluid-handling system that avoids some of the problems of the prior art is disclosed. Some fluid-handling systems in accordance with the present invention are generally suitable for use with products over a wide range of rheological properties, can accommodate wide variations in the amount of fluid being handled, are less maintenance-intensive than some prior art systems, and are capable of performing a variety of fluid-handling functions.
In various embodiments, a fluid-handling system in accordance with the illustrative embodiment of the present invention is capable of performing one or more of the following functions, among any others: receiving and storing one or more fluids, keeping stored fluids separate from one another, mixing two or more fluids to formulate a product, accurately dispensing fluid, and regulating a flow of fluid.
The specific configuration of a fluid-handling system in accordance with the illustrative embodiment is dependent, to some extent, on its intended use. More particularly, certain features or elements are included in some variations of the system but not in some others, as a function of the intended use of the system. Certain elements are, however, basic to all variations of a fluid-handling system in accordance with the present invention. In particular, basic to all variations is a cartridge that has a bladder and a substantially non-expandable housing. The bladder is disposed within the housing.
A fluid-handling system in accordance with the illustrative embodiment optionally includes a drive-liquid delivery device. This device is capable, in accordance the illustrative embodiment, of delivering liquid (xe2x80x9cdrive-liquidxe2x80x9d) to a region that is within the housing but outside of the bladder. When sufficiently pressurized, the drive-liquid exerts a force against the bladder that results in the expulsion any fluids that are contained within the bladder. In other words, the fluid is indirectly xe2x80x9cpumpedxe2x80x9d such that it does flow through the drive-liquid delivery device. Consequently, if a change is made in the fluid (e.g., new ingredients, etc.), it is accommodated, in some embodiments, by changing the bladder. Generally far less cleaning is required to accommodate a change in fluid than for most prior-art liquid handling systems.
In a variation of the illustrative embodiment, drive-liquid is delivered to the interior of the bladder, rather than outside of the bladder. As the bladder expands, it expels any fluids that are contained with the housing (but outside of the bladder). While this variation might entail more maintenance than the illustrative embodiment, it has certain advantages, as described later in this specification.
In some variations of the illustrative embodiment, fluid-handling systems include multiple (i.e., two or more) cartridges that are coupled to one another. In some of those variations, the bladders are also coupled to one another so that fluid can pass from one bladder to the next. Multi-cartridge arrangements are particularly well suited for conducting experimentation, such as, for example, permuting the order in which ingredients are combined to produce a formulation. Multi-cartridge arrangements are also well adapted to mixing fluids by moving them back and forth between adjacent cartridges, possibly through an orifice structured to promote mixing. As suits the requirements of a particular application, multiple cartridges can be configured in serial or parallel fashion, etc.
In some variations of the illustrative embodiment, an optional control system is coupled to a cartridge, enabling the cartridge to be used as a flow regulator. In such variations, a sensor (e.g., a force sensor, etc.) senses a flow rate, pressure, etc., of a fluid that is flowing out of the cartridge. The sensor generates and outputs, to a controller, a signal that is representative of the flow rate (or pressure, etc.) of the fluid. The controller compares that signal to a set point. Based on a deviation between the sensor output signal and the set point, the controller generates and outputs a control signal. The control signal is output to a final control element, such as the drive-liquid delivery device. The control signal alters the operation of the drive-liquid delivery device, etc., as appropriate, to adjust the flow of fluid from the cartridge to a desired rate.
Large changes in the amount of fluid being handled are accommodated, in some variations of the illustrative embodiment, by changing bladder size. In some other variations, the cartridge itself (i.e., housing and bladder) is replaced by a different cartridge (more suitably sized for the changed quantity of fluid).
These and other variations of a fluid-handling system in accordance with the illustrative embodiment of the present invention are illustrated in the Drawings and described further in the Detailed Description section of this specification.